The three-year South West Infant Sleep Scene Study ("SWISS") has been funded by two charities - the Foundation for the Study of Infant Deaths and Babes in Arms - and will be based at the Institute of Child Health in Bristol.

The Bristol research team, led by Professor Peter Fleming and Dr Pete Blair, will study healthy infants in the former Avon area, Somerset and Gloucestershire. The study will build on their previous work identifying factors that affect the risk of infants dying suddenly and unexpectedly as cot deaths. The implementation of these findings has led to dramatic falls in the numbers of cot deaths worldwide.

Over the next three years, 600 families who are expecting a baby will be asked to take part in the study, which will involve questionnaires at regular intervals during the first year after the baby is born. For about 200 of the families there will also be a home visit by one of the research health visitors working on the study, and a video recording of the environment in which the baby is sleeping.

The aim of the study is to understand how subtle differences in the way parents care for their babies at night - many of which may reflect the ways their own parents looked after them as babies - may influence the health, growth and development of their babies.

Professor Fleming said: "It is clear there are many complicated interactions between parents and babies at night, but most of our understanding of mother-baby interactions is based on daytime observations. Babies spend up to two-thirds of their time asleep, so this study will have great value in understanding normal growth and development, and the way this is affected by mother-baby interactions at night."

Dr Blair added: "The information collected from the families of healthy infants in the former Avon area will once again be of value in helping us to develop evidence-based recommendations on how best to care for your baby."